Solar-driven photocatalytic water/seawater splitting holds great potential for green hydrogen production.However,the practical application is hindered by the relatively low conversion efficiency resulting from the ina...Solar-driven photocatalytic water/seawater splitting holds great potential for green hydrogen production.However,the practical application is hindered by the relatively low conversion efficiency resulting from the inadequate utilization of solar spectrum with significant waste in the form of heat.Moreover,current equipment struggles to maintain all-day operation subjected to the lack of light during nighttime.Herein,a novel hybrid system integrating photothermal catalytic(PTC)reactor,thermoelectric generator(TEG),and phase change materials(PCM)was proposed and designed(named as PTC-TEG-PCM)to address these challenges and enable simultaneous overall seawater splitting and 24-hour power generation.The PTC system effectively maintains in an optimal temperature range to maximize photothermal-assisted photocatalytic hydrogen production.The TEG component recycles the low-grade waste heat for power generation,complementing the shortcoming of photocatalytic conversion and achieving cascade utilization of full-spectrum solar energy.Furthermore,exceptional thermal storage capability of PCM allow for the conversion of released heat into electricity during nighttime,contributing significantly to the overall power output and enabling PTC-TEG-PCM to operate for more than 12 h under the actual condition.Compared to traditional PTC system,the overall energy conversion efficiency of the PTC-TEG-PCM system can be increased by∼500%,while maintaining the solar-to-hydrogen efficiency.The advancement of this novel system demonstrated that recycling waste heat from the PTC system and utilizing heat absorption/release capability of PCM for thermoelectric application are effective strategies to improve solar energy conversion.With flexible parameter designing,PTC-TEG-PCM can be applied in various scenarios,offering high efficiency,stability,and sustainability.展开更多
Wireless sensor networks are widely used for monitoring in remote areas. They mainly consist of wireless sensor nodes, which are usually powered by batteries with limited capacity, but are expected to last for long pe...Wireless sensor networks are widely used for monitoring in remote areas. They mainly consist of wireless sensor nodes, which are usually powered by batteries with limited capacity, but are expected to last for long periods of time. To overcome these limitations and achieve perpetual autonomy, an energy harvesting technique using a thermoelectric generator (TEG) coupled with storage on supercapacitors is proposed. The originality of the work lies in the presentation of a maintenance-free, robust, and tested solution, well adapted to a harsh industrial context with a permanent temperature gradient. The harvesting part, which is attached to the hot spot in a few seconds using magnets, can withstand temperatures of 200°C. The storage unit, which contains the electronics and supercapacitors, operates at temperatures of up to 80°C. More specifically, this article describes the final design of a 3.3 V 60 mA battery-free power supply. An analysis of the thermal potential and the electrical power that can be recovered is presented, followed by the design of the main electronic stages: energy recovery using a BQ25504, storage on supercapacitors and finally shaping the output voltage with a boost (TPS610995) followed by an LDO (TPS71533).展开更多
We chose a definition of heatwaves (HWs) that has ~4-year recurrence frequency at world hot spots. We first examined the 1940-2022 HWs climatology and trends in lifespan, severity, spatial extent, and recurrence frequ...We chose a definition of heatwaves (HWs) that has ~4-year recurrence frequency at world hot spots. We first examined the 1940-2022 HWs climatology and trends in lifespan, severity, spatial extent, and recurrence frequency. HWs are becoming more frequent and more severe for extratropical mid- and low-latitudes. To euphemize HWs, we here propose a novel clean energy-tapping concept that utilizes the available nano-technology, micro-meteorology knowledge of temperature distribution within/without buildings, and radiative properties of earth atmosphere. The key points for a practical electricity generation scheme from HWs are defogging, insulation, and minimizing the absorption of infrared downward radiation at the cold legs of the thermoelectric generators. One sample realization is presented which, through relay with existing photovoltaic devices, provides all-day electricity supply sufficient for providing air conditioning requirement for a residence (~2000-watt throughput). The provision of power to air conditioning systems, usually imposes a significant stress on traditional city power grids during heatwaves.展开更多
The thermoelectric energy conversion technique by employing the Disk-Magnet Electromagnetic Induction (DM-EMI) and improved DM-EMIs is shown, and possible applications to heat engines as one of the energy harvesting t...The thermoelectric energy conversion technique by employing the Disk-Magnet Electromagnetic Induction (DM-EMI) and improved DM-EMIs is shown, and possible applications to heat engines as one of the energy harvesting technologies are also discussed. The idea is induced by integrating irreversible thermodynamical mechanism of a water drinking bird with that of a Stirling engine, resulting in thermoelectric energy generation different from conventional heat engines. The current thermoelectric energy conversion with DM-EMI can be applied to wide ranges of temperature differences. The mechanism of DM-EMI energy converter is examined in terms of axial flux magnetic lines and categorized as the axial flux generator. It is useful for practical applications to macroscopic heat engines such as wind, geothermal, thermal and nuclear power turbines and heat-dissipation lines, for supporting thermoelectric energy conversions. The technique of DM-EMI will contribute to environmental problems to maintain clean and susceptible energy as one of the energy harvesting technologies.展开更多
The recent energy crisis and environmental burden are becoming increasingly urgent and drawing enormous attention to solar-energy utilization. Direct solar thermal power generation technologies, such as, thermoelectri...The recent energy crisis and environmental burden are becoming increasingly urgent and drawing enormous attention to solar-energy utilization. Direct solar thermal power generation technologies, such as, thermoelectric, thermionic, magneto hydrodynamic, and alkali-metal thermoelectric methods, are among the most attractive ways to provide electric energy from solar heat. Direct solar thermal power generation has been an attractive electricity generation technology using a concentrator to gather solar radiation on a heat collector and then directly converting heat to electricity through a thermal electric conversion element. Compared with the traditional indirect solar thermal power technology utilizing a steam-turbine generator, the direct conversion technology can realize the thermal to electricity conversion without the conventional intermediate mechanical conversion process. The power system is, thus, easy to extend, stable to operate, reliable, and silent, making the method especially suitable for some small-scale distributed energy supply areas. Also, at some occasions that have high requirements on system stability, long service life, and noiselessness demand, such as military and deep-space exploration areas, direct solar thermal power generation has very attractive merit in practice. At present, the realistic conversion efficiency of direct solar thermal power technology is still not very high, mainly due to material restriction and inconvenient design. However, from the energy conversion aspect, there is no conventional intermediate mechanical conversion process in direct thermal power conversion, which therefore guarantees the enormous potential of thermal power efficiency when compared with traditional indirect solar thermal power technology [1].展开更多
Oscillating heat pipe is a new type of heat transfer. It not only has simple structure, non-pollution and low maintenance cost, but also has high heat transfer efficiency. Semiconductor thermoelectric generation techn...Oscillating heat pipe is a new type of heat transfer. It not only has simple structure, non-pollution and low maintenance cost, but also has high heat transfer efficiency. Semiconductor thermoelectric generation technology is also an environmental technology. This article combines these two kinds of technology. By means of this generate electricity way, we make a set of system and the related experiment. Then we do some research on the feasibility of this system.展开更多
Unmanned systems are increasingly adopted in various fields,becoming an indispensable technology in daily life.Power systems are the lifeblood of unmanned systems,and affect the working time and task complexity.Howeve...Unmanned systems are increasingly adopted in various fields,becoming an indispensable technology in daily life.Power systems are the lifeblood of unmanned systems,and affect the working time and task complexity.However,traditional power systems,such as batteries and fuels have a fixed capacity.Therefore,once the power supply is exhausted and cannot be replenished in time,the unmanned systems will stop working.Hence,researchers have increasingly begun paying attention to renewable energy generation technologies.The principles,advantages,and limitations of renewable energy generation technologies are different,and their application effects in different unmanned systems are also uneven.This paper presents a comprehensive study of the application and development status of photovoltaic,thermoelectric,and magnetoelectric generation technologies in four kinds of unmanned systems,including space,aviation,ground,and water,and then summarizes the adaptability and limitations of the three technologies to different systems.Moreover,future development directions are predicted to enhance the reliability of renewable energy generation technologies in unmanned systems.This is the first study to conduct a comprehensive and detailed study of renewable energy generation technologies applied in unmanned systems.The present work is critical for the development of renewable energy generation technologies and power systems for unmanned systems.展开更多
Recently the concern about energy consumption across the globe has become more severe due to global warming. One essential way to address this problem is to maximize the efficiency of existing renewable energy resourc...Recently the concern about energy consumption across the globe has become more severe due to global warming. One essential way to address this problem is to maximize the efficiency of existing renewable energy resources and effectively eliminate their power losses. The previous studies on energy harvesting of photovoltaic (PV) modules try to cope with this problem using gradient-based control techniques and pay little attention to the significant loss of solar energy in the form of waste heat. To reconcile these waste-heat problems, this paper investigates hybrid photovoltaic-thermoelectric generation (PV-TEG) systems. We implement the generalized particle swarm optimization (GEPSO) technique to maximize the power of PV systems under dynamic conditions by utilizing the waste heat to produce electricity through embedding the thermoelectric generator (TEG) with the PV module. The removal of waste heat increases the efficiency of PV systems and also adds significant electrical power. As a control method, the proposed GEPSO can maximize the output power. Simulations confirm that GEPSO outperforms some state-of-the-art methods, e.g., the perturb and observe (PO), cuckoo search (CS), incremental conductance (INC), and particle swarm optimization (PSO), in terms of accuracy and tracking speed.展开更多
基金supported by the Basic Science Center Program for Ordered Energy Conversion of the National Natural Science Foundation of China(52488201)the National Natural Science Foundation of China(52376209)+1 种基金the China Postdoctoral Science Foundation(2020T130503 and 2020M673386)the China Fundamental Research Funds for the Central Universities.
文摘Solar-driven photocatalytic water/seawater splitting holds great potential for green hydrogen production.However,the practical application is hindered by the relatively low conversion efficiency resulting from the inadequate utilization of solar spectrum with significant waste in the form of heat.Moreover,current equipment struggles to maintain all-day operation subjected to the lack of light during nighttime.Herein,a novel hybrid system integrating photothermal catalytic(PTC)reactor,thermoelectric generator(TEG),and phase change materials(PCM)was proposed and designed(named as PTC-TEG-PCM)to address these challenges and enable simultaneous overall seawater splitting and 24-hour power generation.The PTC system effectively maintains in an optimal temperature range to maximize photothermal-assisted photocatalytic hydrogen production.The TEG component recycles the low-grade waste heat for power generation,complementing the shortcoming of photocatalytic conversion and achieving cascade utilization of full-spectrum solar energy.Furthermore,exceptional thermal storage capability of PCM allow for the conversion of released heat into electricity during nighttime,contributing significantly to the overall power output and enabling PTC-TEG-PCM to operate for more than 12 h under the actual condition.Compared to traditional PTC system,the overall energy conversion efficiency of the PTC-TEG-PCM system can be increased by∼500%,while maintaining the solar-to-hydrogen efficiency.The advancement of this novel system demonstrated that recycling waste heat from the PTC system and utilizing heat absorption/release capability of PCM for thermoelectric application are effective strategies to improve solar energy conversion.With flexible parameter designing,PTC-TEG-PCM can be applied in various scenarios,offering high efficiency,stability,and sustainability.
文摘Wireless sensor networks are widely used for monitoring in remote areas. They mainly consist of wireless sensor nodes, which are usually powered by batteries with limited capacity, but are expected to last for long periods of time. To overcome these limitations and achieve perpetual autonomy, an energy harvesting technique using a thermoelectric generator (TEG) coupled with storage on supercapacitors is proposed. The originality of the work lies in the presentation of a maintenance-free, robust, and tested solution, well adapted to a harsh industrial context with a permanent temperature gradient. The harvesting part, which is attached to the hot spot in a few seconds using magnets, can withstand temperatures of 200°C. The storage unit, which contains the electronics and supercapacitors, operates at temperatures of up to 80°C. More specifically, this article describes the final design of a 3.3 V 60 mA battery-free power supply. An analysis of the thermal potential and the electrical power that can be recovered is presented, followed by the design of the main electronic stages: energy recovery using a BQ25504, storage on supercapacitors and finally shaping the output voltage with a boost (TPS610995) followed by an LDO (TPS71533).
文摘We chose a definition of heatwaves (HWs) that has ~4-year recurrence frequency at world hot spots. We first examined the 1940-2022 HWs climatology and trends in lifespan, severity, spatial extent, and recurrence frequency. HWs are becoming more frequent and more severe for extratropical mid- and low-latitudes. To euphemize HWs, we here propose a novel clean energy-tapping concept that utilizes the available nano-technology, micro-meteorology knowledge of temperature distribution within/without buildings, and radiative properties of earth atmosphere. The key points for a practical electricity generation scheme from HWs are defogging, insulation, and minimizing the absorption of infrared downward radiation at the cold legs of the thermoelectric generators. One sample realization is presented which, through relay with existing photovoltaic devices, provides all-day electricity supply sufficient for providing air conditioning requirement for a residence (~2000-watt throughput). The provision of power to air conditioning systems, usually imposes a significant stress on traditional city power grids during heatwaves.
文摘The thermoelectric energy conversion technique by employing the Disk-Magnet Electromagnetic Induction (DM-EMI) and improved DM-EMIs is shown, and possible applications to heat engines as one of the energy harvesting technologies are also discussed. The idea is induced by integrating irreversible thermodynamical mechanism of a water drinking bird with that of a Stirling engine, resulting in thermoelectric energy generation different from conventional heat engines. The current thermoelectric energy conversion with DM-EMI can be applied to wide ranges of temperature differences. The mechanism of DM-EMI energy converter is examined in terms of axial flux magnetic lines and categorized as the axial flux generator. It is useful for practical applications to macroscopic heat engines such as wind, geothermal, thermal and nuclear power turbines and heat-dissipation lines, for supporting thermoelectric energy conversions. The technique of DM-EMI will contribute to environmental problems to maintain clean and susceptible energy as one of the energy harvesting technologies.
文摘The recent energy crisis and environmental burden are becoming increasingly urgent and drawing enormous attention to solar-energy utilization. Direct solar thermal power generation technologies, such as, thermoelectric, thermionic, magneto hydrodynamic, and alkali-metal thermoelectric methods, are among the most attractive ways to provide electric energy from solar heat. Direct solar thermal power generation has been an attractive electricity generation technology using a concentrator to gather solar radiation on a heat collector and then directly converting heat to electricity through a thermal electric conversion element. Compared with the traditional indirect solar thermal power technology utilizing a steam-turbine generator, the direct conversion technology can realize the thermal to electricity conversion without the conventional intermediate mechanical conversion process. The power system is, thus, easy to extend, stable to operate, reliable, and silent, making the method especially suitable for some small-scale distributed energy supply areas. Also, at some occasions that have high requirements on system stability, long service life, and noiselessness demand, such as military and deep-space exploration areas, direct solar thermal power generation has very attractive merit in practice. At present, the realistic conversion efficiency of direct solar thermal power technology is still not very high, mainly due to material restriction and inconvenient design. However, from the energy conversion aspect, there is no conventional intermediate mechanical conversion process in direct thermal power conversion, which therefore guarantees the enormous potential of thermal power efficiency when compared with traditional indirect solar thermal power technology [1].
文摘Oscillating heat pipe is a new type of heat transfer. It not only has simple structure, non-pollution and low maintenance cost, but also has high heat transfer efficiency. Semiconductor thermoelectric generation technology is also an environmental technology. This article combines these two kinds of technology. By means of this generate electricity way, we make a set of system and the related experiment. Then we do some research on the feasibility of this system.
基金supported by the Key Program of National Natural Science Foundation of China(Grant No.61933002)the National Science Fund for Distinguished Young Scholars(Grant No.62025301)。
文摘Unmanned systems are increasingly adopted in various fields,becoming an indispensable technology in daily life.Power systems are the lifeblood of unmanned systems,and affect the working time and task complexity.However,traditional power systems,such as batteries and fuels have a fixed capacity.Therefore,once the power supply is exhausted and cannot be replenished in time,the unmanned systems will stop working.Hence,researchers have increasingly begun paying attention to renewable energy generation technologies.The principles,advantages,and limitations of renewable energy generation technologies are different,and their application effects in different unmanned systems are also uneven.This paper presents a comprehensive study of the application and development status of photovoltaic,thermoelectric,and magnetoelectric generation technologies in four kinds of unmanned systems,including space,aviation,ground,and water,and then summarizes the adaptability and limitations of the three technologies to different systems.Moreover,future development directions are predicted to enhance the reliability of renewable energy generation technologies in unmanned systems.This is the first study to conduct a comprehensive and detailed study of renewable energy generation technologies applied in unmanned systems.The present work is critical for the development of renewable energy generation technologies and power systems for unmanned systems.
文摘Recently the concern about energy consumption across the globe has become more severe due to global warming. One essential way to address this problem is to maximize the efficiency of existing renewable energy resources and effectively eliminate their power losses. The previous studies on energy harvesting of photovoltaic (PV) modules try to cope with this problem using gradient-based control techniques and pay little attention to the significant loss of solar energy in the form of waste heat. To reconcile these waste-heat problems, this paper investigates hybrid photovoltaic-thermoelectric generation (PV-TEG) systems. We implement the generalized particle swarm optimization (GEPSO) technique to maximize the power of PV systems under dynamic conditions by utilizing the waste heat to produce electricity through embedding the thermoelectric generator (TEG) with the PV module. The removal of waste heat increases the efficiency of PV systems and also adds significant electrical power. As a control method, the proposed GEPSO can maximize the output power. Simulations confirm that GEPSO outperforms some state-of-the-art methods, e.g., the perturb and observe (PO), cuckoo search (CS), incremental conductance (INC), and particle swarm optimization (PSO), in terms of accuracy and tracking speed.
